From: linma <linma@xxxxxxxxxx>
In the cleanup routine for failed initialization of HCI device,
the flush_work(&hdev->rx_work) need to be finished before the
flush_work(&hdev->cmd_work). Otherwise, the hci_rx_work() can
possibly invoke new cmd_work and cause a bug, like double free,
in late processings.
This was assigned CVE-2021-3564.
This patch reorder the flush_work() to fix this bug.
Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx>
Cc: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-bluetooth@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Lin Ma <linma@xxxxxxxxxx>
Signed-off-by: Hao Xiong <mart1n@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/bluetooth/hci_core.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
v2: use "network comment style" for block comment.
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index fd12f1652bdf..7d71d104fdfd 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1610,8 +1610,13 @@ static int hci_dev_do_open(struct hci_dev *hdev)
} else {
/* Init failed, cleanup */
flush_work(&hdev->tx_work);
- flush_work(&hdev->cmd_work);
+
+ /* Since hci_rx_work() is possible to awake new cmd_work
+ * it should be flushed first to avoid unexpected call of
+ * hci_cmd_work()
+ */
flush_work(&hdev->rx_work);
+ flush_work(&hdev->cmd_work);
skb_queue_purge(&hdev->cmd_q);
skb_queue_purge(&hdev->rx_q);
--
2.31.1
